Such networks involve fairly loose semantic associations that are nonetheless useful for human browsing. It is possible to represent logical descriptions using semantic networks such as the Existential Graphs of Charles S. Peirce or the related Conceptual Graphs of John F. Sowa. These have expressive power equal to or exceeding standard first-order predicate logic. Unlike WordNet or other lexical or browsing networks, semantic networks using these can be used for reliable automated logical deduction. Some automated reasoners exploit the graph-theoretic features of the networks during processing.

There are also elaborate types of semantic networks connected with corresponding sets of software tools used for lexicalknowledge engineering, like the Semantic Network Processing System ( SNePS ) of Stuart C. Shapiro or the MultiNet paradigm of Hermann Helbig (MultiNet is an acronym for "Multilayered Extended Semantic Network"). The latter is especially suited for the semantic representation of natural language expressions and used in several NLP applications.

One can consider a mind map to be a very free form variant of a semantic network. By using colors and pictures the emphasis is on generating a semantic net which evokes human creativity.

In the 1960s to 1980s the idea of a semantic link was developed within hypertext systems as the most basic unit, or edge, in a semantic network. These ideas were extremely influential, and there have been many attempts to add typed link semantics to HTML and XML.